Many disposable medical devices such as blood bags, solution containers, administrative sets for blood or solution, and the like are made of a flexible, collapsible polyvinyl chloride plastic. Alternatively, polyolefin type and other materials have been proposed for use as a substitute for polyvinyl chloride plastic. See, for example, Gajewski, et al. U.S. Pat. No. 4,140,162, which discloses polyolefin-type blends for making flexible, collapsible containers.
It may be desirable in many instances to manufacture products, for example medical devices, in which some of the device is made of one type of plastic, for example a polyolefin, while another part of the device is made of a different type of plastic such as polyvinyl chloride. For example, it may be desirable for blood bag having a body made of a polyolefin material to be connected to a donor tube of a polyvinyl chloride formulation.
Unfortunately, polyvinyl chloride is sealingly incompatible with most polyolefin-type materials, so that the maintenance of a sealed, sterile connection between the donor tube and the body of such a blood bag is a substantial technical problem.
Attempts have been made to solve this by various mechanical seals, for example, see Vcelka and Winchell U.S. Pat. No. 4,049,034. However, these mechanical techniques for sealing incompatible materials all involve structure having increased complexity and expense over simpler seals, usable when the materials to be sealed are compatible.
In accordance with this invention, a plastic composition is disclosed which is capable of being formed into a connector member for simultaneously sealing to both polyvinyl chloride plastics and polyolefin plastics, eliminating the need for costly and complex mechanical expedients.
As a result of this, various devices, and specifically medical devices, may be fabricated with various parts made of dissimilar materials and connected together in accordance with this invention. Specifically, a polyolefin blood bag may carry a polyvinyl chloride donor tube, or alternatively a polyvinyl chloride blood bag may carry a polyolefin donor tube, or other parts which are made of polyolefin, with strong, hermetic seals depsite the general incompatibility of the two materials.